Abstract

The U.S. Air Force funds a number of programs for the advancement of technology each year. A three-year program was funded to develop and document machine and CBN electroplated wheel parameters that improve CBN wheel performance in the creep-feed form grinding of aerospace alloys in water-based coolants.

The end user of CBN plated grinding wheels is being challenged to change coolant type due to (1) Safety & Hygiene, (2) Compliance with expanding state and federal regulations, and (3) Reduction of disposal expense while trying to reduce overall production costs.

This paper focuses on the development of an electroplated CBN grinding wheel specification for creep feed grinding of aerospace alloys in water soluble coolants. This optimization study details the important CBN wheel specifications, machine conditions, coolant effects on wheel performance, and operating parameters for grinding in water-based coolants.

Key points

There are many factors which can effect the performance of electroplated CBN form wheels. these factors are interdependent with other elements of the grinding process. Poor performance from any of these elements will result in poor performance from an optimally specified and manufactured grinding wheel. Five major areas that impact CBN wheel performance are:

• Machine Tool Quality
• Initial Conditioning of the Grinding Wheel
• Machine Feed Parameters
• Grinding Wheel Speed (SFPM)
• Grinding Fluids (Types)

Of these five areas, the grinding fluid is probably the most misunderstood, most overlooked factor in optimizing a grinding wheel's performance.

Through the use of statistical methods, engineering disciplines and progressive improvement, we have learned:

• The developed bonding system provides a 77% increased life (Statistical significance at 95% Confidence) in water based coolants from precious standard construction.
• Baseline productivity, established with a straight oil coolant, can be restored (and exceeded) through a combination of the developed bond and implementation of associated grinding process parameters.
• CBN 500 was statistically superior to CBN 570 and ABN 600.
• There is a set of conditions under which a CBN plated wheel can grind a deep form in cobalt with considerable wheel life and part quality.
  

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